1. Field of the Invention
This invention relates to supports that are used in pairs or other multiples to elevate a residential or commercial heating system and allow clearance beneath it to accommodate piping and p-traps and/or meet local building code requirements, specifically to a strong furnace riser block made from plastic materials and molded construction that is configured for placement with one or more other riser blocks under a residential or commercial furnace unit to provide many advantages for installers, including helping to make furnace installations faster and easier without compromised durability or furnace stability, and also without reduced strength or increased cost over the use of prior art metal furnace supports. Similar to some prior art metal furnace supports, present invention riser blocks have a hollow interior and a generally isosceles trapezoid configuration when viewed from any of its four sides, which together allow compact nesting during storage and transport. Yet, as a result of their molded construction, present invention riser blocks are also able to have integral structural features that overcome a problem experienced with prior art metal furnace supports wherein adjacent supports become stuck together and delay installation. Additional features incorporated into present invention riser block design, which are also known in prior art furnace supports, are a deep draft on all four of its sides and an outwardly-directed bottom flange. However, unlike prior art metal furnace supports, which are heavy to move and lift during installation and may also experience a shortened useful life due to a susceptibility to rust and corrosion, present invention furnace riser blocks are lightweight and made from sturdy and durable plastic material that will not rust or crack, they absorb vibration and noise to quiet noisy furnace units, and they also are able to withstand wide ambient temperature variations without reduced performance. Present invention riser blocks further have a large width-to-height ratio, due in part to an enlarged flange width over that observed in prior art metal furnace supports, which provides increased stability for the lightweight riser blocks and is particularly helpful for allowing present invention riser blocks to stay in their designated positions as a heavy furnace is moved across them into its desired position of use. In addition, present invention riser blocks have a flange purposely configured with non-sharp edges and corners to reduce damage to surroundings and installer injury during their handling, vertical ribbing that creates a scalloped configuration to increase/maximize vertical loading capability, and multiple indentations in their top surfaces each dimensioned and shaped for receiving a vibration isolator, or a combination of vibration isolator and mounted metal jacket riser member, which can provide additional clearance under a furnace when required by local building code and/or installation site limitation. Although preferred to quiet noisy furnace units, and unless they are needed to mount a metal jacket riser member within an indentation for added clearance beneath a furnace unit, use of vibration isolators with present invention riser blocks is optional. Furthermore, unless a very large furnace unit is to be installed, not all of the indentations in a present invention riser block will be used to support the furnace unit, and it will be the installer's choice to select which of the indentations present are best suited to support of the furnace unit's weight and provide ideal positioning of the furnace unit for facilitated piping and p-trap connections. Thus, present invention riser block configuration provides many more advantages for furnace installers to reduce their business operating cost than prior art metal furnace supports. First, as a result of structural and material choices disclosed herein, present invention furnace riser blocks are strong and durable, and they have been shown to be ten times stronger than known metal furnace supports. Also, their manufacturing cost is comparable to (or less than) prior art metal furnace supports, particularly when multiple present invention riser blocks are made from one sheet of plastic material for cost efficient manufacture. In addition, present invention riser blocks are configured for instant adaptability with vibration isolators and metal jacket riser members, so that one-size-fits-all for easy and prompt installation of different sizes of furnace unit and facilitated connection of piping and p-traps even when installation site limitations are encountered.
2. Description of the Related Art
Furnaces currently installed in residential and commercial buildings are often part of HVAC systems that perform a combination of heating, ventilating, and air conditioning functions. Furthermore, furnaces are selected for installation according to the volume of air in a building that requires temperature and humidity modification, and as a result furnaces can vary widely in size, weight, and perimeter configuration. In addition, many furnaces also require a clearance of at least six to seven inches beneath them to accommodate piping and p-traps. Since furnaces are heavy and time consuming to install, any technology improvements that facilitate furnace installation are appreciated by installers, including improvements that standardize installation for different sizes of furnace unit, as well as improvements that make furnace installations faster and more cost efficient to perform. The present invention furnace riser block is such a technology improvement and provides many advantages to installers to help them accomplish furnace installations more efficiently and with less physical effort, as well as with increased cost efficiency and reduced time spent at an installation site.
Furnace supports made from metal are widely known and in current use to provide the clearance needed for running piping and p-traps beneath a furnace unit, or as otherwise dictated by local building code. While known metal furnace supports are non flammable and provide other benefit to installers, present invention riser blocks made from molded plastic provide installer with many additional advantages and improvements. In addition to being heavy to lift and move during installation, known metal furnace supports have sharp edges and corners capable of injuring an installer, damaging surroundings, and/or sufficiently digging into a plastic fluid collection pan placed under a furnace unit to cause premature pan failure. Also, metal furnace supports are known to rust or crack after extended use, and they do not provide any vibration dampening to quiet noisy furnaces. Furthermore, should an installer have an installation where higher furnace clearance is required by local building code or unexpected installation site limitation, metal furnace supports have no readily available feature to use for providing a quick remedy. In contrast, present invention furnace riser blocks are made from durable and strong load-bearing plastic material that will not rust or crack, and which is further unaffected by exposure to temperature extremes. In addition, present invention riser blocks each have several alternatively used top surface indentations at each end thereof that are configured to receive a vibration isolator, or a combination of a vibration isolator and a metal jacket riser member mounted thereon. The selection of indentations provided by present invention riser blocks enhances their versatility to accommodate different sizes of furnace unit, installed furnace positioning, and variable clearance requirements. Furthermore, present invention riser blocks and vibration isolators to be used therewith are configured to reduce the development of stress cracks in the riser blocks, as well as in any fluid collection pan placed beneath them, during furnace installation as a heavy furnace unit is moved across their top surfaces. In addition, the large width-to-height ratio of the spaced-apart, lightweight, and independently positioned present invention riser blocks (which are not placed in physical contact with one another during furnace unit support) helps each one to maintain its stability and desired positioning during furnace unit installation and use. Furthermore, the structural features of the present invention riser blocks have been selected to minimize pressure points and keep thin or weak spots from developing in its material as its multi-level structure is formed, which could otherwise lead to crack development, premature material deterioration, and/or riser block failure during extended use. Additional goals guiding the selection of structural features and materials to be used as a part of the present invention riser blocks include a sturdy construction that facilitates installation, shortens installation time, provides stable installation, provides trouble-free long-term use, and minimizes maintenance after installation. Another objective for present invention manufacture is to produce a riser block that will last as long as the useful life of the furnace unit it supports, which present invention riser blocks are expected to do. Trying to develop a plastic riser block that was comparable (or lower) in cost to allow competition in the marketplace with prior art metal furnace supports was also a challenge to the inventor herein, since present invention riser blocks needed to be made from non-flammable material that is unaffected by exposure to wide temperature fluctuations, have the strength to support a heavy furnace unit during extended use measured in years with little or no inspection/maintenance, and be easily adaptable to provide additional clearance beneath a furnace unit in selected applications where needed by local code or installation site limitation. In addition, the inventor herein wanted nesting capability for compact riser block storage and transport without adjacent riser blocks sticking together, vibration dampening capability that would help to quiet for noisy furnaces, and structural design features that allow plastic to be pulled in optimal directions during manufacture from a single sheet of material so that the resulting material in the rise block after manufacture lacks pressure points and weak spots, allowing it to support a heavy furnace unit during extended use measured in years. No other furnace riser block is known with the same structure, to function in the same manner, or provide all of the features and advantages of the present invention.